This invention relates to devices, actuated by temperature, for controlling fluid flow, ie, thermostats, and is particularly directed to a new and improved thermostat utilizing the expansion/contraction properties of metal hydride in response to variations in temperature.
The hydrogen adsorping properties of a hydride are known and one use of such properties in the prior art is disclosed in the U.S. Pat. No. 3,122,728 to Lindberg, Jr. in which the volumetric expansion/contraction of hydrogen gas absorbed and desorped by metal hydride was used to expand and contract a blister which actuated a switch in a control circuit. In this prior art device only the volumetric expansion/contraction of the gas was used but no attempt was made to use the expansion/contraction properties of the hydride itself to mechanically open and close a valve as a means of controlling flow in response to fluid temperatures.
Accordingly, it is an object of this invention to provide a metal hydride thermostat in which both the expansion/contraction properties of hydride and the volumetric expansion/contraction of the adsorped and desorped gas are used to provide a device which operates as a thermostat.